The present invention relates to a novel retrovirus from the HIV group, as well as to variants or parts thereof which contain the essential properties of the virus. A process is described for culturing the retrovirus. The invention furthermore relates to the isolation of this retrovirus and to use of the virus, its parts or extracts for medicinal purposes, for diagnostics and in the preparation of vaccines.
Retroviruses which belong to the so-called HIV group lead in humans who are infected by them to disease manifestations which are summarized under the collective term immunodeficiency or AIDS (acquired immune deficiency syndrome).
Epidemiological studies verify that the human immunodeficiency virus (HIV) represents the etiological agent in the vast majority of AIDS (acquired immune deficiency syndrome) cases. A retrovirus which was isolated from a patient and characterized in 1983 received the designation HIV-1 (Barrxc3xa9-Sinoussi, F. et al., Science 220, 868-871 [1983]). A variant of HIV-1 is described in WO 86/02383.
A second group of human immunodeficiency viruses was identified in 1985 in West Africa (Clavel, F. et al., Science 233, 343-346 [1986]) and designated human immunodeficiency virus. type 2 (HIV-2) (EP-A-0 239 425). While HIV-2 retroviruses clearly differ from HIV-1, they do exhibit affinity with simian immunodeficiency viruses (SIV-2). Like HIV-1, HIV-2 also leads to AIDS symptomatology.
A further variant of an immunodeficiency retrovirus is described in EP-A-0 345 375 and designated there as HIV-3 retrovirus (ANT 70).
The isolation of a further, variant, immunodeficiency virus is also described in Lancet Vol. 340, September 1992, pp. 681-682.
It is characteristic of human immunodeficiency viruses that they exhibit a high degree of variability, which significantly complicates the comparability of the different isolates. For example, when diverse HIV-1 isolates are compared, high degrees of variability are found in some regions of the genome while other regions are comparatively well conserved (Benn, S. et al., Science 230, 949-951 (1985]). It was also possible to observe an appreciably greater degree of polymorphism in the case of HIV-2 (Clavel, F. et al., Nature 324, 691-695 [1986]). The greatest degree of genetic stability is possessed by regions in the gag and pol genes which encode proteins which are essential for structural and enzymic purposes; some regions in the env gene, and the genes (vif, vpr, tat, rev and nef) encoding regulatory proteins, exhibit a high degree of variability. In addition to this, it was possible to demonstrate that antisera against HIV-1 also crossreact with gag and pol gene products from HIV-2 even though there was only a small degree of sequence homology. Little hybridization of significance likewise took place between these two viruses unless conditions of very low stringency were used (Clavel, F. et al., Nature 324, 691-695 [1986]).
Owing to the wide distribution of retroviruses from the HIV group and to the fact that a period of a few to many years (2-20) exists between the time of infection and the time at which unambiguous symptoms of pathological changes are recognizable, it is of great importance from the epidemiological point of view to determine infection with retroviruses of the HIV group at as early a stage as possible and, above all, in a reliable manner. This is not only of importance when diagnosing patients who exhibit signs of immunodeficiency, but also when monitoring blood donors. It has emerged that, when retroviruses of the HIV-1 or HIV-2 type, or components thereof, are used in detection systems, antibodies can either not be detected or only detected weakly in many sera even though signs of immunodeficiency are present in the patients from which the sera are derived. In certain cases, such detection is possible using the retrovirus from the HIV group according to the invention.
This patent describes the isolation and characterization of a novel human immunodeficiency virus, designated below as MVP-5180/91 (SEQ ID NO:56), which was isolated from the peripheral lymphocytes of a female patient from the Cameroons who was 34 years old in 1991 and who exhibited signs of immunodeficiency. From the point of view of geography, this retrovirus originates from a region in Africa which is located between West Africa, where there is endemic infection with HIV-2 and HIV-1 viruses, and Eastern Central Africa, where it is almost exclusively HIV-1 which is disseminated. Consequently, the present invention relates to a novel retrovirus, designated MVP-5180/91 (SEQ ID NO:56), of the HIV group and its variants, to DNA sequences, amino acid sequences and constituent sequences derived therefrom, and to test kits containing the latter. The retrovirus MVP-5180/91 (SEQ ID NO:56) has been deposited with the European Collection of Animal Cell Cultures (ECACC) PHLS Centre for Applied Microbiology and Research, Porton Down, Salisbury Wilts. SP4 OJG, United Kingdom, on Sep. 23, 1992 under ECACC Accession No. V 920 92 318 in accordance with the stipulations of the Budapest Treaty. The ECACC is located at the PHLS Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wilts, SP4 0JG, U.K. The deposit was made on Sep. 23, 1992, and was assigned Accession No. V 920 92 318. The date of notification of acceptance of the culture was Jan. 21, 1993.
As do HIV-1 and HIV-2, MVP-5180/91 (SEQ ID NO:56) according to the invention grows in the following cell lines: HUT 78, Jurkat cells, C8166 cells and MT-2 cells. The isolation and propagation of viruses is described in detail in the book xe2x80x9cViral Quantitation in HIV Infection, Editor Jean-Marie Andrieu, John Libbey Eurotext, 1991xe2x80x9d. The procedural methods described in that publication are by reference made a subject of the disclosure of the present application.
In addition to this, the virus according to the invention possesses a reverse transcriptase which is magnesium-dependent but not manganese-dependent. This represents a further property possessed in common with the HIV-1 and HIV-2 viruses.
In order to provide a better understanding of the differences between the MVP-5180/91 (SEQ ID NO:56) virus according to the invention and the HIV-1 and HIV-2 retroviruses, the construction of the retroviruses which cause immunodeficiency will first of all be explained in brief. Within the virus, the RNA is located in a conical core which is assembled from protein subunits which carry the designation p 24 (p for protein). This inner core is surrounded by a protein coat, which is constructed from protein p 17 (outer core), and by a glycoprotein coat which, in addition to lipids, which originate from the host cell, contains the transmembrane protein gp 41 and the coat protein 120 (gp 120). This gp 120 can then bind to the CD-4 receptors of the host cells.